The present invention refers to a track for track-type vehicles, in particular for track-type vehicles used for preparing ski slopes, comprising a plurality of bands extending parallel to one another, said bands being aligned in the direction of motion and having transversely secured thereto a large number of steel crosspieces, which, when seen in cross-section, are equipped with a U-shaped yoke composed of two U-legs and of a connection web extending therebetween, the first U-leg being provided with a connecting leg as an extension, which extends inwards via a bend, and, after an additional bend, with a sword following said connecting leg and extending approximately parallel to said U-legs.
A steel crosspiece of the above-mentioned type is known from practical experience. It is primarily used on hard ground, e.g. on icy slopes. It is constructed as an open profile and has an asymmetrical cross-section. In view of the fact that the shear center in the case of this open profile is located outside of the geometry, high torsional stress will occur. Likewise, high bending stress will occur as well.
The known steel crosspiece consists of high-quality quenched and tempered steel, which causes substantial production difficulties. Straightening and stamping processes are necessary, and a heat treatment has to be carried out as well. This often entails the risk of distortion. The steel crosspieces often have to be readjusted, and this can result in a formation of capillary cracks.
Due to the asymmetrical nature of the profile, it is necessary to produce separate steel crosspieces for the left and for the right track, and this increases the manufacturing costs.
Other problems arise in connection with the fastening of the track crosspieces to the guide yokes for driving as well as in connection with the bands.
In particular when driving on a piste, the bands are affected at the point of connection with the crosspieces and they are partly destroyed. The guide plates and spike holders normally provided on such crosspieces are arranged in a disadvantageous manner on the known crosspieces and cannot be secured optimally.
Light metal crosspieces used for tracks and belonging to a different class of device are known from practical experience as well; these light metal crosspieces are already provided with a symmetrical profile. Most of them are manufactured as an extruded part, and they are equipped with a comparatively thickened base portion tapering towards the sword. In order to be able to provide a sufficient connection between the light metal crosspieces and the bands, the crosspieces are equipped with a central web, which is normally provided with a tapped hole for the fastening screws.
Light metal crosspieces of this type are used in soft snow. They offer the advantage of low weight and of a high moment of resistance. They are, however, not cheap and they wear within a comparatively short period of time.